1. Field of the Invention:
This invention relates to a method of detecting the presence of cancer and to a reagent for use therein. Moreover, it relates to a novel low molecular weight binding protein for use in the cancer detection method and to a method of preparation of the binding protein and preparation of the CoA-SPC.
2. Description of the Prior Art:
Early detection stands today as one of the most effective means for combating cancer. During the past several years, numerous methods have been reported for the detection of cancer. Some of these have been physical, while others are chemical in nature. Most of the physical methods, such as mammography and X-ray, have had reasonable success in the detection of cancer, but the hazards of radiation may be greater than is generally believed, and may outweigh their value.
Of the chemical assays (see, for example, U.S. Pat. Nos. 3,673,410, 3,697,638 and 3,663,684), the carcinoembryonic antigen (CEA) assay (Gold and Freedman, J. Exp. Med., 121, 439-462 (1965); Gold and Freedman, J. Exp. Med., 122, 467-481 (1965); and Thomson et al,. Proc. Nat. Acad. Sci., 64, 161-167 (1969)) has been most extensively publicized, and has been subject of extensive investigation. However, the CEA assay appears to have its greatest potential value in the area of cancer management and not detection. There are mixed opinions in regard to the usefulness of the CEA assay for the routine diagnosis of cancer in the clinic and in population screening (Stevens et al., Br. J. Cancer, 32, 147-151 (1975)).
As a result, early detection of cancer generally must rely on the early appearance of easily observable symptoms such as skin lesions, lumps etc.. Moreover, in many cases detection of even such symptoms must rely on a fortuitous observation by the patient himself.
Consequently, there is a critical need for a reliable method of screening patients for the presence of cancer.